The present invention relates to a process for verification of an identification element by direct comparison of an optical image of the identification element with the reconstruction of a hologram formed of the identification element, and in addition it relates to a device for carrying out this process.
This invention is intended to provide increased safety from falsification of identity cards, check cards, credit cards, customer's cards and other identification elements, which are intended to identify their owner.
A known identification and security system uses a hologram in or on an identification element, such as an identity card or other card. The hologram contains information in coded form, which can be re-read under special optical conditions only. This information is recorded by forming a hologram on a suitable recording material using, as the object, the card with the personal data thereon. The hologram is subsequently joined with the card, for example, by inserting the recording material containing the hologram into an aperture provided in the card or by fixing it to the back of the card.
The card is verified in a special reading device. For this purpose, it is inserted into a slot on top of said reading device and thereby assumes the correct position for verification. Inside the reading device a conventional light source is provided producing a direct image of the card, as well as a laser for the reconstruction of the hologram made of the card. On a ground glass or frosted plate put into the front wall of the reading device two images appear adjacent to one another, namely, the direct image of the card produced by means of white light and the red reconstruction of the card resulting from the hologram. By visual comparison of the two images it is possible to determine if the card corresponds to its holographic image.
In said reading device the direct comparison of the two images is rather time-consuming, if any falsification of or tampering with the card is to be detected, since the two images have to be compared characteristic by characteristic. Comparison is made difficult by a difference in color between the reconstruction of the hologram and the direct image of the card. If a number of cards have to be verified in succession, the person performing the check may, after some time, get tired and be subject to a slackening of concentration, because he/she has to change his/her direction of sight several times for each individual card. Thus a possible falsification or tampering may be overlooked.